Mobility Study Warns of Gridlock, Pollution

CAMBRIDGE, Massachusetts, October 30, 2001 (ENS) - People's insatiable appetite for mobility is heading the world's transportation systems toward unsustainable gridlock and environmental degradation unless several grand challenges are tackled, conclude Massachusetts Institute of Technology researchers and colleagues in report on worldwide mobility at the end of the 20th century.

The MIT researchers warn that by 2015, greenhouse gas emissions from transport in the developing world will exceed those in the industrialized world unless manufacturers and municipalities can improve the fuel economy of cars and trucks and curb traffic growth. Grand challenges to that end include reinventing public transport and creating a portfolio of mobility options for people and freight.


Rush hour traffic in Atlanta, Georgia, one of the United States' smoggiest cities (Photo courtesy Georgia Department of Transportation)
"Transportation is essential for moving people and goods, but it also has a broader role. It shapes our cities, stimulates economic growth and makes possible societal interactions. Unfortunately, it also has harmful side effects that must be looked at carefully and systematically," said Daniel Roos, associate dean for engineering systems, director of the Engineering Systems Division and one of three MIT project leaders.

The study, "Mobility 2001," was conducted by MIT and Charles River Associates and is the first phase of a three year study commissioned by the World Business Council for Sustainable Development (WBCSD). The goal of the overall initiative is to develop a global vision of sustainable mobility for 2030 and possible pathways to get there.

The six month, million dollar first phase study was a joint effort of the Laboratory for Energy and the Environment, and the Engineering Systems Division. MIT researchers from 10 departments, laboratories and centers collaborated to assess the current state of mobility and its impacts in a holistic way.

Those involved drew on expertise gained in other ongoing studies that consider mobility and global warming, transportation networks, transportation technology for 2020 and mobility demand forecasts for 2050.

Eleven fuel and auto companies from the World Business Council for Sustainable Development sponsored the study.

mack truck

Freight transportation using tractor-trailer rigs uses energy and produces carbon emissions (Photo courtesy Mack Trucks Inc.)
"We're fortunate to be collaborating with this group," said David Marks, professor and director of the Laboratory for Energy and the Environment. "If we're going to understand the major challenges and then plan and implement change, it's critical that auto manufacturers and energy companies together come up with ideas about how we can move toward sustainable mobility and present those ideas to stakeholders."

The report considers both passenger and freight and all modes of transport (ground, air and ocean). It looks at mobility's impact on economic development, social welfare and environmental quality.

The study considers both developed and developing countries, incorporating information gathered at stakeholder meetings with environmentalists, governments, researchers, students and consumer groups around the world.

"Other studies of mobility tend to focus on only part of the problem - one country or one mode of transport, for example," said John Heywood, the Sun Jae Professor of Mechanical Engineering and director of the Sloan Automotive Laboratory. "We've attempted to make this study both broad and comprehensive."


The assessment paints a sobering picture of trends in automobile travel. In the developed world, the auto is the main provider of mobility in virtually all urban areas.

soy bus

Fuel efficient new buses could run on soybean based fuel, known as biodiesel (Photo courtesy National Renewable Energy Laboratory)
Urban sprawl is increasing as the affluent move to the suburbs, where low population densities make public transport difficult. New highways can not be built fast enough to keep up with the increasing traffic, largely due to concerns about associated environmental and social disruption.

In the developing world, rapid population growth, urbanization and the startup of suburbanization are making conditions worse. Increasing prosperity has led to an increase in the number of private vehicles.

Rapidly growing megacities have little time or money to build public transport systems or to expand roads to handle the new traffic. The result is serious congestion, economic and environmental damage, and major safety problems. Energy use and associated emissions are skyrocketing, in part due to the use of older cars and dirtier fuels.


Analyses of the environmental impacts of our mobility systems generally focus on greenhouse gas emissions and climate change. But building and using roads, bridges, airports and harbors also degrade local and regional ecosystems, damage natural habitats and kill off species, leading to loss of biodiversity.


Air transport is responsible for eight to 12 percent of transportation related carbon emissions (Photo courtesy UK web online)
These impacts may be more damaging in the long term than generally recognized.

The environmental impacts of airplanes in flight are also often underestimated. Air transport is responsible for eight to 12 percent of transportation related carbon emissions. But because the carbon is emitted at high altitude, its potential impact on global warming is twice as great as that of carbon emitted at ground level.

Freight transportation systems are also an unexpectedly large source of carbon emissions. Current freight transportation is relatively energy efficient, but it uses about 43 percent of all transportation energy.


Trains leave a smaller environmental footprint and are more fuel efficient compared to other modes of transport (Photo courtesy Railway Association of Canada)
The need to transport goods over longer distances is increasing, and the ongoing competition for road space between freight and passenger traffic is a growing global problem. Transportation of goods over long distances is already fairly efficient, but the last few miles of delivery - for example, from supermarkets to homes - is not.

Another concern is that more than 96 percent of the world's transportation depends on petroleum. Petroleum yields high energy density fuels that will be hard to beat. Petroleum burning vehicles are becoming more fuel efficient and cleaner, but thus far those improvements have been offset by factors such as growth in the vehicle fleet, increased driving, and use of larger and faster vehicles.


In summarizing their findings, the researchers identified the following set of grand challenges that, if successfully addressed, would dramatically improve the sustainability of mobility.

Technological change can play a major role in addressing most of these challenges, the researchers said. But there is one more overarching challenge, the team said - to create the institutional capability and political will needed to tackle such complex, long term issues.


U.S. studies show that vehicle emissions now account for 75 percent of the carbon monoxide, 33 percent of the carbon dioxide, and 44 percent of the nitrogen oxides in the urban air (All photos courtesy National Renewable Energy Laboratory)
The Sustainable Mobility Project team will now move to its next phase: devising strategies aimed at making mobility sustainable over the coming decades.

The "Mobility 2001" report is available at: